Production of artificial straw



Jan 8, 1935. w. F. RICHTER 1,986.979

PRODUCTION OF ARTIFICIAL STRAW Filed Jan. 2. 1931 I WITNESSES A/ jljENTOk (w 246;. 3.49M, gfiawd oam T 1 mo uenomr mrmciinsralw l2 'lwi lliam i tki'chter, po o, Pa.', assig nor:to.Cl1em ical Holding Corporation, Apollo,

poration" of Delaware V i-his invention mate to the production of .artificialstrawk" precipitation joffa cellulose solution; for example is then treated: "in if the manner I known in the art. Strawpreparedirithismanner is commonly characterized by irregularities in. width and strengthi] The freshly precipitated-bands are 10 weak} and in drawingt m precipitat' ing loath there is'a tendency forthe band to fold in? an irregulanmanner. -This1is" objectionable artificialstraw which is characterized by uniform 20 width 'andj strejrig'th, is of improved quality and strongerthanthat made heretofore, and which may be produced by an ethod. and "apparatus" which" are simple, require no material modification of existing practice, and do not increase the cost of the product.

The invention may be described in connection with the accompanying drawing, in which Fig. l is a side view of an apparatus which may be used comprising a folder guide provided with a groove into which the freshly formedband is drawn with its longitudinal axis aligned with the root of the groove. 7

Having reference now to the accompanying drawing, which shows the preferred embodiment of the invention, a cellulosic band is formed by passing a cellulose solution, such as viscose, continuously through a spinneret into a suitable precipitating bath. In the case of viscose the bath may comprise a solution, of about 6 per cent of sulfuric acid, 2 per cent of bismuth sulfate,

and 1 percent of zinc sulfate, as described and devised, prior to my invention, for-forming artiin the preferredpractice of the invention; 'Fig. I

;Applicationlanuary, 1931, Serial No. 5506,1795 v H *iifablaims. (o is;j s7

claimed in mych -pending application Serial of the spinneret, not shown, is in the form of' an elongate slit whose opening is :of substantially uniform section; The'a'gi 'oaratusused in pr'ecipi 5 tatingsuch cellulose'solutions including thespinnerets'; 'are so well known in the art as to require no further illustration or description." i i In this manner there is" formed a band hav ing substantiallyflat uninterrupted faces, and off 10 root of thegroove, as shownin Fig. 2. r I 4 The folder guide isflpreferaly of cylindrical section, with thefolding' groove formed peripher-f 20- ally therein; and most suitably the groove is deepi In the preferred embodiment of the invention these guides areformed from glass; by butt sealing two=pieces"of rounded endglass rod, as may be understood from Fig. 3. In making such seals the area of butt contact is preferably kept as small as possible, in order to provide the deep groove referred to. I

The tension on band 1 as it is drawn over the guide causes the band to be drawn into and conform to the groove. This creates a folding pres: sure which causes the band to, be doubled, the fold following the longitudinal axis. This may be seen from Figs. 1 and 2, in which band 1 is doubled as it leaves guide 2 to form a narrower 35 doubled band4. In the preferred embodiment of the invention the doubled band is then passed over a godet 5 to a spinning pot 6, driven in any suitable manner, where it is collected in the manner customary in the art. The cakes thus collected are thensubjected to appropriate finishing treatm'entasuch as desulfurizing, bleaching, dyeing, or washing, as the case may be. i In general it is preferable to so dispose guide that an obtuse angle is formed between the fresh- .ly formed. band passing to amuse folded band leaving it, as seen in Fig. 1. To this end band 1 as it leaves the precipitating bath may be, and preferably is, passed over an ordinary'cylindrical guide 7, Figs. 1 and 2, which increases the tension on the band and thus assists in producing folding in guide 2. The folding pressure due to forcing the band into the groove may be increased or decreased by shifting the position of guide 7 to vary the angle thus formed.

Straw formed in accordance with this invention is of superior quality, as compared withprior products. There is no tendency for the bandto be broken or weakened mechanically at the fold so that the folded edge has full strength. Also, since the folding takes place while theband is freshly formed and before it has fully hardened,

the edges folded together seal themselves. Consequently edge-[continuity is obtained. Also,lfold ing prior to full penetration of the precipitating bath encloses a certain amount of the bath within the band, so that hardening or coagulation then takes place from the center outwardly; and vice versa. Since the folded bands are of heavier section than it has been possibleto reauce.sans-- factorily by direct precipitation, they possess markedly improved strength. In consequence of these and other factors, the artificial straw thus produced is of superior quality, not only as-;re-

, 1. In an apparatus for making artificial straw & the;combination with means for forming acellulose solutioninto a continuous cellulosic band, a spinning pot for collecting said band, driving means operatively connected to said spinn-ingipot, amid; a godet, of a? guide for said: band disposed between-saidiorming meansand godet; said guide having a band-receiving folding groove adapted to fold-aband passed thereover. g

2*. In an apparatus for making artificial straw I the combination with-meansf'or forming acellulose solution into a continuous cellulosic band, a godet, a spinning pot for collecting said band, and driving means operatively connected to said spinning pot, of a circular guide for said band between said forming means and godet, the guide being provided with a deep peripherally formed bandreceiving folding groove having rounded side walls and being adapted to fold a-bandvpassedthereover.

3'. In an apparatus for making artificial'straw the combination of a spinneret having a slit of substantially uniform section, a godetmounted above said spirmeret, a spinning pot, driving meansoperatively connected to said spinning pot, andaglassguide supported between said spinneret go'd'et and provided with a deep peripherally formed folding groove having rounded side walls.

4; A method of making artificial straw, comprising precipitating viscose in the form of a continuous fiat band of substantially uniform thickness from edge to" edge andhaving-isubstantially flat plane surfaces, drawing said band-continuous ly from the precipitating bath, and whilestill freshly precipitated mechanicallydoubling theband uniformly along its lonigtud-inal axis'to form a narrower band of substantially-uniform widthandofsubstantially uniform'thickness from edge to-edge; I p v 5; In anapparatus for making artificial straw, the combination with means for forming acellulose solution into a continuous cellulosic band having substantially flat plane surfaces and of substantially uniform cross-section from edge to edge, and-meansfor collecting said band including a godet, of a-guide supported-between; said forming. means and godet andxhaving a folding groove formed between converging curved side walls for receiving and folding said bandysaid guide 'recei-ving the band in saidgroeve, and. said groove acting to foldthe band uniformly alongits-longitudinal axis as it passes from the'tor ming-means to e godeti i. WILLIAM F. RICHTER; 

